I've got some small domain names that I host on my home server and would like to get some basic email addresses for those domains. I set up an Ubuntu 12.04 server and followed the instructions here for setting up a mail server with Postfix and Courier:
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After doing all that, I attempted to set up my firstname.lastname@example.org
email address in Thunderbird, but it can't find the server.
I'm able to telnet into port 25 locally (i.e. telnet 127.0.0.1 25) and send myself a test message manually, but I can't telnet into port 25 from another computer. My ISP has informed me that they do not block any ports.
Pingability.com returns the following information about my mail server: There was a problem while talking with the mail server. Got 'ConnectException: Connection refused'
nmap -p 25 example.com yields the following:
PORT STATE SERVICE 25/tcp filtered smtp
What are my next steps to troubleshoot/resolve this? I'm at a dead end.